Endogenous NKT cells participate in the rejection of spontaneous chemically induced tumors as well as in the maturation of dendritic cells capable of presenting tumor antigens. Co-administration of NKT cell activators with known tumor protein antigens is one approach by which the anti-tumor functions of NKT cells might be harnessed and focused towards specific malignancies. Conventional alpha/beta T cells and NKT cells are born from a common bi-potent progenitor cell. Although the signals and genes activated during conventional ab T cell development have been identified, those involved in NKT cell development remain largely a mystery. Considering the potential anti-tumor utility of NKT cells, a more detailed insight into the events essential for development of this unique lineage is highly desirable. Using oligonucleotide microarrays, we aim to identify gene expression events occurring during a specific NKT developmental transition, and to bioinformatically trace these gene expression events in a proximal direction, towards established molecular signaling pathways. To gauge the significance of these gene expression events, their function will be examined in an inducible in vivo murine model of NKT lymphocyte development. [unreadable] [unreadable]